Flax and hemp, reinforcement for composites
Material composites using European linen and hemp fibers with their renewable and agricultural origins are incorporated in areas such as the automobile industry which utilizes thermo-plastic or thermo-set templates. Now available to the general public, many products in the sport and leisure industries also use the technical advantages of linen composites. Ideal for everyday use, linen and hemp composites also have a reinforced position in the conception and design of homes. Plus they have a clear potential in avant-garde sectors such as the aeronautics or railway industries.
|The automotive market is undergoing massive changes. Under growing pressure from environmental regulations, builders are tightening specifications for their equipment manufacturers. To reduce CO2 emissions and shrink the environmental footprint of transportation, the market is demanding more lightweight materials that are recyclable at end-of-life.
Parts that are either already being produced or under development are:
– hidden interior parts such as door panels, rear seat shells, sound insulation for bulkheads, rear window shelves, and dashboards;
– structural parts such as floors, under-the-hood parts, degas tank caps, air ducts for centre and side ventilators, and rear-view mirror support frames.
|MOBILITY AND TRANSPORT
|By 2015, just like regular cars, motorised conveyances like scooters, electric cars and light vehicles will have to comply with European Directive 2000/53, which requires recycling 85% of end-of-life car components and recovering 95%. In these ecological times, biodegradability and recyclability are becoming priorities that must be taken into account in the design of parts, so flax and hemp fibres will inevitably develop over the short term.
|SPORTS AND LEISURE
|Applications using thermoplastic and thermoset composites reinforced with flax and hemp fibres are both environment friendly and technical, so there could be significant market potential in the sports and leisure sector. At present, although flax fibres can be used either alone or in combination with carbon fibres in thermoset resins to produce structural parts (frames or hulls in the sports sector) and the advantages have already been amply demonstrated, only 8% of annual flax-fibre production is used in composites.
|There are more and more prototypes for sailboats made of flax fibre reinforced composites, since they are highly appreciated for their lightness, manoeuvrability, gliding qualities and environment friendliness.
|Fans of environment-friendly habitats are always looking for lightweight, recyclable and hypoallergenic materials, so natural-fibre construction materials are very popular with them. There are more and more of these consumers, and they pay a lot of attention to the environmental properties of materials, as much to preserve nature as to clear their homes of the “pollution” of allergenic materials. The return to “local product” values constitutes yet another potential opportunity for composites reinforced with flax and hemp – fibres that are grown in Europe.
|While convenience goods might appear to be only a niche market for flax, the sector is turning out to be an attractive vehicle for communication as an ideal means to publicise the appeal of composites for everyday tools and accessories.
Now that consumers are aware of the need for environmental protection, they are able to appreciate that flax is a renewable, recyclable resource which helps to reduce the need to use fossil-fuel raw materials.
|STREET FURNITURE ( SIGNAGE AND URBAN FURNITURE )
|The use of flax or hemp in composites has environmental and economic advantages that are becoming imperative:
– unlike glass fibre, flax and hemp fibres can be incinerated with a net zero carbon footprint and without leaving residues, and thus be upgraded into energy;
– compared to aluminium, processing these fibres consumes much less energy, thereby reducing cost. As regards mechanical properties, flax and hemp fibres are:
– strong, and about as stiff as glass fibre;
– less likely than glass fibre to cause cuts if they break;
– lightweight, facilitating transport and handling.
|Integrating flax fibre into the wind turbine manufacturing process is part of a global eco-design process.
A prototype for wind turbine rotor blades was created using a 40% flax textile reinforcement co -mingled with a PLA matrix. The flax/PLA fabrics were compression moulded (hot compacting) to make extremely strong blades.
|Today, the aerospace sector already accounts for 4% of the composite market, and specialists are forecasting an 11% increase or more by 2014. The aerospace sector, which has very high standards when it comes to testing the reliability of its materials, is taking an interest in flax fibre composites. These new-generation materials are currently included in aerospace research and development programs, but before being definitively incorporated into aircraft construction, they need to be tested over a period of at least ten years.|
|The railway sector has potential: the time is ripe to develop high-speed trains designed entirely to fill the needs of an international market in compliance with technical specifications for interoperability (TSI). That sector is also rallying to take environmental concerns into account. Beyond issues like component recyclability or biodegradability, specifiers are concerned with producing lighter railway vehicles not only to achieve higher speeds and optimum energy savings, but also to decrease braking time in order to optimise the number of trains circulating. Another consideration is that operators pay fees that are indexed on the vehicle weight. In this context, flax and hemp offer definite advantages, thanks to their good mechanical properties.|
|Plastics currently account for more than 40% of the packaging sector, compared to barely 1% for biomaterials. Current regulations require the recycling of at least 72% of household packaging materials.
These new-generation materials have a number of advantages, including low weight and good mechanical strength even in thin layers. The use of hollow fibres like flax and hemp help to absorb moisture, which is a significant advantage in the food sector.
|In the design sector, flax and hemp fibres are used mostly to create structural parts. Designers are very interested in their intrinsic properties, which include strength, low weight, flexibility, agreeable touch, lack of abrasiveness, UV resistance and biodegradability. These pioneering designers develop more or less limited series and do not hesitate to use flax and hemp composites to create complex shapes. The fibres usually show at the surface of the finished product, as the flax and hemp are an integral part of the aesthetics.
|MUSIC & AUDIO
|Flax’s low density and vibration damping capability are serving in new applications to
produce or retransmit music according to high acoustic standards.
|Given that the aesthetic aspect of flax composites sometimes appeals to
manufacturers, in particular in the field of sports, it goes to say that “naturalness”
as a feature is also giving rise to new creations in the field of personal equipment,
where the combination of form and functionality is on display.